Control of power actuated machinery



M.rh1e,194 s." H. H. BROWNLEE 2,313,911

CONTROL OF POWER ACTUA'IED MACHINERY Filed Jan. 29, 19:8 2 Sheets-Shut 13 INVENTOR M flaeatwrwaxv Bean M52 may W ATT'O R N EY March16,1943. H H;BRQWNLEE 2,313,917

CONTROL OF POWER ACTUATED MACHINERY Filed Jan. 29, 1938 2 Sheets-Sheet 2ATTORNEY v Patented Mar. 16, 1943 CONTROL OF POWER ACTUATED MAC IIINERYHenry Herbertson Brownlee, New Yorka N. Application January 29, 1938,Serial No. 187,593

12 Claims.

This invention relates to the 'art of controllin power actuatedmachinery. It is of special utility in association with machines thatoperate quick- 1y, repeatedly and with great force as in power pressesworking on materials of various sorts. It is exemplified herein asapplied to a garment pressin connection with which, it has specialadvantages. Its objects are simplicity of operation, speed andefficiency of working and security against accidents.

In the laundry and tailoring business numerous types of machines areused for the pur- I pose of ironing and pressing garments after thewashing or dry cleaning operations. A common machine for this step isoperated by pneumatic force applied to a heated ironing head, or buck,to bring it down and hold it under pressure against a garment thatthemachine attendant had adjusted upon'a padded, and sometimes also heated,lower .buck.

To work such a machine it is necessary the attendant to exercise controlof compressed air for the energization of the pneumatic device. Handoperated air valves have been used for this purpose and, to protect theattendant from ac-v cidentally operating the press with one hand whileadjusting the garment on the lower buck with the other, a dual controlsystem requiring the joint use of two hands to close the press has beenresorted to. Under that system the attendant must keep both hands ontheair valve controls until the head has been locked in the ironingposition; This expedient, however, affords no protection to othersshould they thoughtlessly intrude the danger 'zone. As the space betweenthe bucks when the press is open may be approached from all sides, thepossibility of such intrusion is a hazard especially in a busy laundrywhere numerous machines are in operation and many workers are movingabout.

A machine equipped according to this invention is safe because it isrendered inoperative, or, if started, is immediately restored, by themere presence near its working parts, or by the approach thereto fromany direction, of the attendant or of any other person or body of likecapacity. 'Simplicity of operation, speed and emciency are securedbecause it is only necessary for the attendant to step away from themachine 50 .upwardly extending bracket 5 supports a rocker .in order tocause the power to be applied and whereby on the attendants' returnand,in the application of the invention to a garment press, on either suchreturn or the drying of the garment in the press, whichever happensfirst, the

power is disabled and the machine is restored to for its normal positionin readiness for a subsequent operation.

The invention serves with special advantage where the operation of agroup of machines is 5 supervised by a single attendant. By placing themachines in line or arranging them about a central area the attendant isfree immediately after preparing one machine for operation to pass tothe next in line and so on in rapid succession. The movements can be sotimed that when the last machine has been attended to the work in thefirst is finished.

These and other desirable characteristics of the invention are securedby the maintenance within a space surrounding the machine, or eachmachine of a group, or the danger zone thereof, of a field of energysensitive to the movement into and out of it of external bodies, and bysuitable power applying and power disabling controlling apparatusresponsive to theresulting' energy effects. Power disablement is alsoprovided on failure of the controlling apparatus to function normally.In presses for ironing damp garments, the controlling apparatusis causedto be responsive to maintain and then to disable the power by and withthe aid of suitable devices sensitive to the moisture content of thegarments themselves or to other effective evidence of the completion ofthe ironing operations.

In the drawings:

Fig. 1 is a sideelevatlon of a garment pressing machine.

Fig. 2 is a vertical cross section of a magnetic air valve.

Fig. 3 is a diagrammatic representation of a system oi. controllingcircuits. 7

Fig. 4 is a diagrammatic plan view of a group of machines.

Fig. 5 is a plan view, in outline, of a typical 40 ironing head showingan effective location of a plurality of auxiliary devices fordetermining the duration of the ironing period of damp garments, and

Fig. 6 is an end view of an alternative ironing head, partly in section,equipped with a thermostatic device. l

- The press base or frame i supports a tablelike top 2, on which ismounted a goose neck support 3 for a lower or padded buck 4. An

arm 6, which carries at its forward end an upper or ironing back I. Arearward extension 10 by a system of levers working on the toggle Whenthe air is thus let in the piston descends pushing down on one arm of abell crank II and, at the end of its stroke, bringing the other armalmost into alignment withthe link It, thereby greatly adding to theforce exerted on the garment. On the release of the air the retractilesprings i5, i6 aided by the counterweight 8 open the press.

ment moisturecontrolled switches 41. The oscillator and the other partsof this circuit arrangement, except the magnetic air valve ii and thegarment moisture controlled switches 41,

may be assembled in a box or container 48 (see may be arranged accordingto standard engi- The valve provides for a short passage forthecompressed air through the duct l2a to the cylinder 10 and, therefore,for quick action both in closing andopening the press. This valve hastwo plugs, better shown in Fig. 2, one, i1, normally closing the inleti8 to the outlet it leading to the cylinder. The other II, is normallyopen position to an exhaust outlet 2!. The plugs are joined by a spacerpin 22. A magnet 23 when energized by electric current in its coil 24attractsthe armature 25 which depresses a plunger 2} against a spring 21which in turn presses down a'second plunger 28 to close the valve 20 andto open it at 11. The re,- verse action occurs when the magnet isdeenergized. This structure may be supported by a bracket 29 to thebaseor frame I.

In the circuit diagram Fig. 3 the garment press is shown-in generaloutlinewith the figure of an attendant "a standing by. A protecting andcontrolling field' of energy is indicated by the space 30 within thedotted line surrounding the press. This space by suitable adjustments is.eifective to a depth of several inches and may neering practice. Thisentire circuit diagram typifies one of many controlling arrangementssuitable for carrying out the operating features of the invention.

' Assuming the oscillator has been started and .the field of energyaround the press established, the operation is as follows: Normally,with the attendant "a, and all other external bodies of ample capacity,outside the energized space, the oscillations generated are adjusted tobe such that in the output circuit the tuned' shunt l3, oiiers a lowimpedance to current fiow and relay ll receives insuillcient current forits energization. when, however, the attendant approaches the press forthe purpose, say, of adjusting a garment therein the capacity of theinput circuit of the oscillator is increased, in consequence of whichthe frequency of the oscillations is changed-in this case lowered. Atsuch lowered frequency the tuned shunt 43, ll oii'ers a higher impedanceto the current from the coil 30. Relay 4! thereupon attracts itsarmature, opens contacts and Bi and closes contact it.

As the protection relay I9. at such times as the oscillator is working,is energized by the B batbe limited, if desired. to a zone near thedangerous working parts. The press should be supported a few inchesabove the fioor, as shown,

or it may be otherwise insulated from ground oran insulated screenadjoining the press may be utilized to define the field of energy, inwhich latter case the press may be grounded.

A convenient way to generate this field of energy'is to provide anoscillator of high frequency which may be several hundred kilocycles,and such oscillator may be of any known type. As shown it is of thethree element vacuum tube type-3i having input and output cells 32, 38,

inductively coupled-:In-the input circuit the coil 32 and condenser 34,together with the concoil 38 of the transformer is a relay 4! in serieswith a rectifier 42, which may be the copper oxide -type.- This'relay isshunted by a tuned circuit comprising an inductance l3 and condenser 44.Relay ll controls a locking relay 45 and these two relays jointlycontrol theoperation' of the magnetic air valve l I. Also controllingthe circuit of the magnetic air valve and the circuit of the lockingrelay 4! is a release relay' 4 the coil of which is in series with oneor more gartery 38 there is now a closed circuit from battery 53 throughthe back contact 54 of release relay ll, front contact 52 of relay 4iand the coil of relay 4! which relay thereupon closes its contacts 55and I6. This relay 45 is now locked in a circuit from battery 53 throughthe contact of relay 39, back contact 54 of relay 48 and its own contactI6.

The attendant having adjusted the garment steps away from the pressthereby removing her body from the energized field 3O whereupon thenormal frequency of the oscillator is restored and thetuned circuit 0,again eflectively shunts current from relayji. This relay 4i thereuponis deenergized and its normal contacts "and II become again closed. Nowthe magnetic air valve is in a closed circuit from the battery Itthrough contact of relay 8|, back contact Q4 of relay 4', back-contactll oi relay 4i and. front contact II of relay 4!. This causes compressedairto be applied to close the press. If during the descending movementof the press any external object such as the attendant or another personenters the field 30 the press will immediately be released by theopening'of the circuit of the air valve at contact 50 of relay ll.Without such outside influence, however, the press closes andv the airvalve comes under control of the garment switches 41, (Fig. 5). or 41s,

. (Fig.6), which, will close, efiectiveiy. by reason of current fiow'through the moisture of the garment, whenplaced flush with the ironinghead as in Fig. 5, or, likewise, by reason of the cooling eilect oi thegarment, if thermostatically sensitive and placed in a compartment justabove the ironingsurface as in Fig. 6. One or more of these. garmentswitches now closes its contact, due to the moisture or coollng'eiiect-age 13,91?

of the garment, and relay 46 is energized in a circuit from battery 53,through contact of relay 39 one or more of the closed switches 41 andback contact of relay 4i. The closure of contact 51 of relay 48 providesan independent path from the battery 53 to the coil of the magnetic airvalve II. In this operation relay 48 also opens contact 54 releasing thelocking relay 4!. In a few seconds the reverse operation of the switches41, or 41a, takes place due to the drying, or heating of the garment,releasing relay 46 and opening the circuit of the air valve. This causesthe release of the press and the lifting of its ironing head. Thegarment is now properly dried and ironed and the press-is ready foranother operation; v

The protection relay 39, which, as stated, becomes energized when theoscillator is in operation, will release, opening all circuits fed'bythe battery 53 and thus disable the power for the press, on any failureof normal operation of the oscillator.

A convenient arrangement for the control 0 a group of three presses J2and 83 is shown in Fig. 4. The attendantifla, having adjusted a garmentin press 6|,leit it to automatically close, adjusted another in press 62and left it with like result, is here shown in the act of adjusting athird garment in press 63.. On leaving the latter, it, too, willautomatically close and, due to an appropriate time schedule ofoperations, pressil will have opened or be about to open, whereupon thecycle of operations, as stated, may forthwith be repeated. At the leftof the attendant is a table 64 for a supply of damp garments and a rack65 for supporting garments that have been ironed and dried,

I claim: v

'1. A power operated garment press, means for maintaining within a spaceadjoining the press a field of energy sensitive to movements relativethereto of external bodies, a device responsive to the moisture contentof a garment in the press, and power applying and disabling means underthe joint control of said energy maintaining means and said device andrendered effective to close the press only upon the movement of such abody from a position within to.

a position outside of said space and to open the press either upon themovement of such a body from the position outside to a position withinsaid space or upon a certain reduction of the moisture content of saidgarment.

2. A press having coacting members for ironing garments and the like,power mechanism for closing the press, and a controlling system for saidpower mechanism including an electric generator adapted to maintainwithin a space surrounding the machine a-field of energy and beingsensitive in its energy output to the movement of external bodies insaid space, and in- A cluding means in the vicinity of at least one ofsaid members to set up a condition sensitive to the moisture content ofa garment in the press,

apparatus associated with said generator and responsive to variations inthe energy output thereof for controlling the application of power toclose said press, and apparatus associated with.said moisture sensitivemeans and responsive to variations in the condition thereof forcontrolling the disabling of power to open said press. a,

3. A textile press comprising a stationary buck member, a, pivotedpressing head member, fluid power motor means to actuate saidhead mem-10 movement of the press head member.

4. A textile press comprising two pressing members, one of which ismovable towards and away from the other, fluid power motor means toactuate said movable member, an electrically actuated valve to controlsaid fluid motor means, an electric system including a thermionic devicewith a control grid and a conductor extending from said grid to thepress, said system producing an electric field in the vicinity of saidmembers and having two conditions of operation, said thermionic devicebeing sensitive to said field and causing the system to change from onecondition of operation to the other when a body of a predeterminednature passes into and out of said field, and a relay controlled by the,condition of the system to cause the actuation of said valve to controlthe movement of the press head member.

5. A textile press comprising a stationary buck motor means foractuating said head, a valve for controlling said head member, anelectromagnet for controlling said valve, an electrode insulatedlymounted on one of said members, a conductive .path for said electrodesubject to resistance variation when said head member is actuated, saidelectromagnet being adapted when energized to actuate said valve to movesaid head member towards the buck member and when deenergized to actuatesaid valve to move the head member away from the buck member, meanscontrolled at will to cause the initial ,energization oi saideiectromagnet, and means 'controlled automatically in response to thevariation of resistance in saidconductive path to temporarily maintainthe energization of said electromagnet to holdthe head member down I onthe buck member and finally to cause the deenergization thereof to movesaid head member away from the buck member.

6. A textile press comprising two pressing members, one of which ismovable towards and away from the other, fluid power motor means toactuate said movable member, a valve for controlling said motor means,an electrode insulatedly mounted on one of said members, a conductivepath for said electrode subject to resistance variation when saidmovable member is actuated,

,operator controlled means to actuate said valve to move said movablemember toward the other variation of resistance in said conductive pathto cause the said circuit to change from one condition of operation tothe other to actuate said valve to movesaid movable member away fro theother member. s

'7. A textile press comprising two pressing members, one of which ismovable towards and away from the other, fiuld power motor means toactuate said movable member, a valve for controlling said motor means,an electrode insulatedly mounted on one of said members, a conductivepath for said electrode subject to resistance variation when saidmovable member is member, a pivoted head member, fluid power member, anelectric circuit having two conditions of operation, and meansresponsive to the actuated, a system of electric circuits having twoconditions of operation for controlling said valve, operator controlledmeans to cause said system to change from one condition of operation tothe other to open said valve to move said movable member towards theother member, and means in said system to render the system responsiveto the variation of resistance in said conductive path to'close saidvalve to move said movable member away from the other member.

8. A textile press comprising two pressing members, one of which ismovable towards and away from the other, fluid power motor means toactuate said movable member, an electrode insulatedly mounted on one ofsaid members, a conductive path for said electrode subject to resistancevariation when said movable member is actuated, a, system of electriccircuits having two conditions of operation for controlling said valve,operator controlled means to cause said system to change from onecondition of operation to another to open said valve to move saidmovable member towards the other member, and means in said system torender the system responsive to the variation'of resistance in saidconductive path temporarily to maintain said valve open to hold saidmovable member down upon the other member and finally to close saidvalve to move said movable member away from the other member.

9. A machine having two work members, one of whichis movable into andout of engagement with the other, motor means to actuate said movablemember, an electrode insulatedly mounted on one of said members, aconductive path for said electrode subject to resistance variation whensaid movable member has been moved into engagement with the othermember, electro responsive means adapted when energized to actuate saidmotor means to move said movable.

member into engagement with the other member and when deenergized tomove said movable member out of such engagement, means controlled atwill to cause the energization of said electro responsive means, andmeans controlled automatically in response to the variation ofresistance in said conductive path to cause the deenergization of saidelectro responsive means.

10. A machine, power means iorworking said machine, an electricgenerator, electroresponsive means under the control of said generatorand controlling in turn the application of said power means to saidmachine, and conducting means said generator with the aid of saidconducti means maintaining within a space surrounding said machine afield of electrostatic energy sensitive' to movements of external bodiesin said space, and said generator being reactively sensitive to saidheld and responding upon a predetermined change in the energy thereofcaused by such a movement to effect an operation of saidelectroresponsive means to work the machine and upon another suchpredetermined change to effect an operation of said electro responsivemeans to stop the working of the machine.

11. A garment press, power meansfor closing and opening said press, anelectric generator for controlling the application of said power meansto said press, conducting means extending from saidgenerator to saidpress, said generator with the aid of said conducting means maintainingwithin a space surrounding the press a field of electrostatic energysensitive to movements of external bodies in said space, said generatorbeing reactively sensitive to said field and responding upon apredetermined change in the energy thereof caused'by such a movement toeffect an operation of said power means to close the press, andcontrolling means associated with a garment in the press and sensitiveto the moisture content thereof, said controlling means being responsiveupon a predetermined reduction of the moisture in the garment to effectan operation of said power means to open the press.

12. A machine, power means for working said machine, an electricgenerator, electroresponsive mechanism under the control of saidgenerator and controlling in turn said power means, and conducting meansextending from said generator to said machine, said generator with theaid-oi said conducting means maintaining within a space surrounding saidmachine a field of electrostatic energy sensitive to movements ofexternal bodies into and out of said space, said generator beingreactively sensitive to said field and responding upon a predeterminedchange in the energy thereof caused by the movement of such a body outof said space to effect an operation of said mechanism to work themachine and responding upon another predetermined change in the energythereof caused by the entrance of such a body to said space to eflect asecond operation of said mechanism to stop the working thereof.

H. HERBERTSON BROWNLEE.

extending from said generator to said machine.

